A tool head having a main body (2) that is rotatable about a tool head axis (5), a slide (6) for holding a cutting tool, the slide (6) being guided on the main body (2) in a slide guide (8) in a linearly moveable manner transversely to the tool head axis (5), and a clamping device (48) for clamping the slide (6) on the main body (2). The clamping device (48) has a clamping body (50) that is adjustable parallel to the tool head axis (5), the clamping body (50), in a clamping position, pressing a sliding face (46) of the slide (6) against a guiding surface (44) of the slide guide (8) with a clamping force (F.sub.N) being introduced.

A cutting tool for boring (40) that is attached to a machining apparatus and used for cutting a hole (13) on a large-diameter side of a stepped hole of a workpiece (10) is provided. The cutting tool for boring (40) is a set of two tools, and each cutting tool for boring (40a, 40b) in the set of two includes a shaft part (41), a cutting blade (42) laterally protruding from the respective shaft parts (41), and an abutment surface (43) formed at the tip of each shaft part (41) and used to cause the tips of the respective shaft parts (41) to butt against each other. Each cutting tool for boring (40a, 40b) performs cutting while the two cutting tools for boring (40a, 40b) rotate integrally around the center line of the shaft parts (41) in a coupled state in which the tips of the cutting tools for boring (40a, 40b) are butted together.

A rotary cutting tool includes a support structure having a central hub located at an axially rearward end of the rotary cutting tool. A plurality of primary support members extends from the central hub in different axial and radial directions in three-dimensional space with respect to a central, rotational axis of the rotary cutting tool. The support structure may include one or more secondary support members extending from a primary support member in different axial and radial directions in three-dimensional space, and one or more tertiary support members to increase stiffness of the support structure. The central hub extends in a plane that is substantially perpendicular to the central, rotational axis of the rotary cutting tool. In one embodiment, each of the plurality of primary support members have a different physical dimension.

An apparatus that includes a tool head; an insert that is coupled to the head and configured to engage an inner diameter of a workpiece, so as to machine the workpiece; a boring bar or drill tube coupled to the head, the boring bar or drill tube configured to extend through a guide bore in the workpiece; and a measuring device that is positioned proximate to the head and configured to measure a radial dimension, an axial dimension, or both of the inner diameter. The head may include a plurality of inserts, wherein the plurality of inserts are selectable such that the inserts are engageable with the inner diameter of the workpiece. The measuring device may include a contact-based measuring device.

Provided is a vibration-proof structure capable of more effectively reducing rotational vibration of a rotating body during a cutting operation. According to a configuration of the structure, inside a main body of the rotating body, there are provided a plurality of shaft members arranged along a longitudinal direction of a rotation axis of the rotating body and at least one layer of multiple tubular members fitted over the shaft members and arranged coaxially with the rotation axis along the longitudinal direction of this rotation axis; and a boundary position between the shaft members adjacent each other in the longitudinal direction and a boundary position between the tubular members adjacent each other in the longitudinal direction are set as different positions along the longitudinal direction.

Provided is a vibration-proof structure capable of more effectively reducing rotational vibration of a rotating body during a cutting operation. According to a configuration of the structure, inside a main body of the rotating body, there are provided a plurality of shaft members arranged along a longitudinal direction of a rotation axis of the rotating body and at least one layer of multiple tubular members fitted over the shaft members and arranged coaxially with the rotation axis along the longitudinal direction of this rotation axis; and a boundary position between the shaft members adjacent each other in the longitudinal direction and a boundary position between the tubular members adjacent each other in the longitudinal direction are set as different positions along the longitudinal direction.